Hope: An individual motive for social commerce.

The authors suggest that people of all ages are goal oriented and that 2 related thought processes typically accompany this goal-related thinking. First, there are pathway thoughts, which tap the perceived capability to generate 1 or more workable routes to desired goals. Second, there are agentic thoughts, which reflect the perception that one can initiate and sustain movement toward a goal along the given pathways. Together, pathway and agentic goal-directed thinking define hope in the present model. After describing how hope develops, the self-report instruments for measuring hope in children and adults are reviewed. How hope is sustained in the context of larger groups is explored, and the importance of shared goals as the foundation of communal hope is described. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theory and simulation on the threshold of water breakdown inducedby focused ultrashort laser pulses

A comprehensive model is developed for focused pulse propagation in water. The model incorporates self-focusing, group velocity dispersion, and laser-induced breakdown in which an electron plasma is generated via cascade and multiphoton ionization processes. The laser-induced breakdown is studied first without considering self-focusing to give a breakdown threshold of the light intensity, which compares favorably with existing experimental results. The simple study also yields the threshold dependence on pulse duration and input spot size, thus providing a framework to view the results of numerical simulations of the full model. The simulations establish the breakdown threshold in input power and reveal qualitatively different behavior for picoand femto-second pulses. For longer pulses, the cascade process provides the breakdown mechanism, while for shorter pulses the cooperation between the self-focusing and the multiphoton plasma generation dominates the breakdown threshold     

Static fatigue and time to failure predictions of particulate filled epoxide resin composites

The long term strength of two composites under constant load has been measured at various temperatures during a period of up to 2 years. Based on the concepts of linear elastic fracture mechanics, times to failure were predicted from short term experiments. The parameters necessary for the analysis were determined using either the double torsion test technique or by measurements of tensile strength at constant stressing rates. It has been found that both procedures lead to nearly equivalent predictions of the static fatigue behaviour of laboratory specimens from room temperature almost up to the glass transition temperature. Deviation of the predictions from experimental long term data are minor and are thus well acceptable for engineering design.     

Effective Bloch equations for semiconductor lasers and amplifiers

A set of effective Bloch equations is established for semiconductor bulk or quantum-well media. The model includes the nonlinear carrier-density dependence of the gain and refractive index and their respective dispersions (frequency dependences). A comparative study is performed between the full microscopic semiconductor Bloch equations and this effective model for pulse propagation to show the range of validity of the present model. The results show that this model agrees well with the microscopic model provided carrier depletion is the dominant saturation mechanism relative to the plasma heating. The effective Bloch equations provide an accurate and practical model for modeling amplifiers with pulses of duration greater than a few picoseconds. By capturing the large bandwidth and the carrier density dependence of the gain, it also provides a reliable model for studying the complex spatiotemporal multilongitudinal and transverse mode dynamics of a variety of wide-aperture high-power semiconductor lasers. The model goes beyond the traditional rate equations and is computationally much more efficient to simulate than the full model     

Phosphorus,phosphorous, and phosphate

This article distinguishes the terms “phosphorus, phosphorous, and phosphate” which are frequently used interchangeably. We point out the difference between phosphorus and phosphate, with an emphasis on the unit of measure. Expressing a value without the proper name or unit of measure may lead to misunderstanding and erroneous conclusions. We indicate why phosphate must be expressed as milligrams per deciliter or millimoles per liter and not as milliequivalents per liter. Therefore, we elucidate the distinction among the terms “phosphorus, phosphorous, and phosphate” and the importance of saying precisely what one really means.     

The influence of sodium on liking and consumption of salty food

Excessive sodium (Na) intake has been linked to development of hypertension and related pathologies. In this study, we assessed if the sodium chloride (NaCl) concentration in a prototypical food influences the liking and intake of that food. In study 1, detection and recognition thresholds for NaCl were assessed, and perceived salt intensity and liking for hash browns of varying sodium concentrations (40 mg, 120 mg, 170 mg, and 220 mg Na/100 g) were compared in a lab setting. In study 2, detection and recognition thresholds for NaCl were assessed in a lab setting, and lunches consisting of hash browns, basic salad, and beverages were consumed freely in a dining setting on 4 separate occasions. Intake and liking ratings for hash browns were recorded after the lunch. In both studies, detection and recognition thresholds for NaCl were not associated with perceived saltiness, liking, or intake of hash browns. Liking and perceived salt taste intensity of hash browns were correlated (r = 0.547 P < 0.01), and in study 1 the 220 mg sodium hash brown was most liked (P < 0.05). In study 2, there was no association between Na concentration and liking or consumption of hash browns. In summary, liking of hash browns were influenced by whether testing was in a lab or dining room environment. In a dining room environment, large decreases (>50%) of sodium content of food were achievable with only minor decrease in liking and no effect on consumption of the food.     

Colour of muscle from 18-month-old steers given long-term daily exercise

Darker beef from pasture-fed compared with grain-fed cattle may result from differences in physical activity rather than differences in nutrition. The objective was to determine if steers that were exercised produced darker meat than non-exercised steers and whether any effect was muscle-related. Exercised steers were walked 4.41 km daily in a single bout, six days per week for 18 weeks at an average speed of 5.2 kmh(-1). All steers were fed grass silage on an ad libitum basis plus 6 kg concentrates. Following slaughter, muscle colour coordinates ('L' (lightness), 'a' (redness) and 'b' (yellowness) values) of M. longissimus dorsi (LD), M. semimembranosus (SM) and M. extensor carpi radialis (ECR) were recorded at 48 h postmortem and redness and yellowness were used to calculate muscle hue ('H') and colour intensity/saturation ('C'). The pH of all muscles was measured at 1.5, 3, 6, 22 and 48 h postmortem and LD samples were recovered (90 min postmortem) for glycolytic potential (GP) assessment. Exercise did not affect muscle lightness, yellowness, hue or colour intensity. However, LD was the darkest (P<0.001) and SM the most saturated (P<0.001) muscle. Exercise affected muscle redness in a muscle-dependent manner (muscle×exercise, P=0.038) whereby ECR became more red with exercise but LD and SM were unaffected. There were muscle×time (P<0.001) and time×exercise (P=0.045) interactions for muscle pH. The ECR muscle had the highest pH at all times. The exercised steers had higher (P<0.05) LD muscle pH than control steers at 3 and 6 h postmortem. Exercise did not affect myoglobin concentration, which was muscle dependent, decreasing in the order: SM (6.72 mg/g)>ECR (6.33 mg/g)>LD (5.48 mg/g), which were all different (P<0.001). Exercise had no effect on GP in LD muscle (111 vs. 99 μmol/g for control and exercised steers, respectively; SED=6.6 μmol/g). It was concluded that although application of exercise did not affect muscle lightness and thus, did not cause 'darker' meat, it did affect muscle redness in a muscle-dependent manner.     

Carcass and meat quality of finishing Friesian steers fed the β-adrenergic agonist L-644,969

The effect of the β-adrenergic agonist L-644,969 on selected parameters of carcass and meat quality was examined in Friesian steers. Four groups of 18 steers were individually offered ad libitum a pelleted diet that contained 0, 0·25, 1·0, or 4·0 ppm L-644,969 for 12 weeks prior to slaughter. L-644,969 quadratically increased carcass weight (3·7, 9·3, and 8·5%, P < 0·001) and altered the distribution of lean meat such that a greater (0·3–5%; P < 0·01) proportion was in the more valuable cuts. There were no effects of L-644,969 on carcass-chill loss and on the water-holding capacity of the longissimus thoracis et lumborum (LTL) muscle. The intramuscular-fat concentration of the LTL was decreased (27–50%; P < 0·01) and the effects on muscle ultimate pH were small and commercially unimportant. Fibre-optic-probe measurements of the LTL indicated darker (P < 0·01) meat due to β-agonist treatment. L-644,969 increased the shear force required to cut through cooked muscle from the LTL (159%, 209%, and 217%, P < 0·001). It is concluded that L-644,969 treatment improved the quantity and distribution of lean in the carcass but impaired meat quality, primarily through a reduction in tenderness.